
class Base{
    public Base(String s){
        System.out.print("B");
    }
}

public class Test extends Base{
    public Test (String s) {
        super(s);//当子类继承父类需要先初始化继承过来的父类的成员，此时需要通过super来完成
        System.out.print("D");
    }
    public static void main(String[] args){
        new Test("C");
    }
}

/* import java.util.Scanner;

public class Test{

    public static void main(String[] args) {
        Scanner scanner = new Scanner(System.in);
        while (scanner.hasNextInt()) {
            int x = scanner.nextInt();
            int y = scanner.nextInt();
            int z = scanner.nextInt();
            Sub sub = new Sub(x, y, z);
            System.out.println(sub.calculate());
        }
    }

}

class Base {

    private int x;
    private int y;

    public Base(int x, int y) {
        this.x = x;
        this.y = y;
    }

    public int getX() {
        return x;
    }

    public int getY() {
        return y;
    }

}

class Sub extends Base {

    private int z;

    public Sub(int x, int y, int z) {
        //write your code here
        super(x,y);
        this.z = z;
    }

    public int getZ() {
        return z;
    }

    public int calculate() {
        return super.getX() * super.getY() * this.getZ();
    }

} */

/* class A{

}

class B extends A{

}

class C extends  B{

}
public class Test {
    public static void main(String[] args) {
        A a0 = new A();
        A a1 = new B();
        A a2 = new C();
    }
} */
